Bottom hole choke



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Patented Sept. 30, 1947 BOTTOMr HOLE CHOKE Frank F. Bridwell, Alic YMorrison, deceased,

e, Tex., and George W. late of Alice, Tex., by Clara Y Pauline Morrison,executrix, Alice, Tex.

Application July 10, 1944, Serial No. 544,202

'7Y Claims.

This invention relates in` general to bottom hole chokes and moreparticularly has reference to a Wire line bottom hole choke assemblycapable of being run inrand Withdrawn through tubing having restrictionsabove thechoke receiving portion thereof. K'

Wire line bottom hole chokes which may be run in the tubing, latched inplace and withdrawn therefrom as constructed heretofore have consistedof a hollow body of tubular formation. For the purpose of holding such abody down, it has been customary in the past to employ slips which arewedge-shaped members with upwardly directed teeth on their outersurfaces and so arranged that when they are moved downwardly withrespect to the body on which they are mounted they will also moveoutwardly so as to grip the inner wall of the tubing and prevent upwardmovement of the body.

Quite often it is desirable to have restrictions in the tubing necessaryfor certain types of gas lift equipment and it would be desirable tohave a choke assembly of such size as to pass by saidv restrictions. Itwas impossible to construct'the previously used types of bottom holechoke in such manner as to accomplish this result because slips have alimited amount of possible expansion. Theoretically the expansion ofslips is limited to their thickness at* their thicker ends but actuallythe expansion of slips is in practice limited to approximately halfoftheir maximum thickness. Obviously the thicker the slips are made thethicker it will be necessary to make the mandrel or body on which theyare mounted, and if this mandrel or body is to have a passageway throughthe central portion thereof,'the strength of materials available and thesizes of the 'flow openings requiredfbecomes such that the `making of astructure small enough in diameter to pass through substantialstrictures in the tubing becomes an impossibility,

The principal object of this invention is to provide a bottom hole chokestructure which mayv be substantially smaller vin overall size than thetubing in which it is to be used so that it may pass restrictions in thetubing such as restrictions occasioned by the employment of certaintypes of gas lift apparatus.

Another object'of this invention is to provide a bottom hole chokestructure having a latching assembly and means for suspending a chokefrom (c1. 16s-21) l the latch assembly for communication with the spacewithin the well tubing about the latch assembly, and means forpositioning and anchoring the latching assembly Within the tubing with-A out restricting the flow from the space within said the latch assemblyfor communication with the space within the well tubing about the latchassembly. Y f

tubing about said latching assembly up through the tubing.

With these and other objects in view as will appear more fullyhereinafter the present invention resides in the parts and combinationsshown inthe drawing and set forth in the following description.

In the drawing:

Figure l is anaxial sectional View of the lowerl portion of well tubinghaving a bottom hole choke according to the present invention locatedtherein in unlatched position.

Fig. 2 is a view similar to Fig. 1 showing the bottom hole choke inanchored position.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is an enlarged detail sectional view of a portion of Fig.'2showing the details of the latch-r ing mechanism.

An embodiment ofthe present invention is shown in the drawing applied tothe lower end of the well tubing l As illustrated, a special fitting orcoupling 2 is secured to the lower end of the tubing I. This fitting hasa tapered bore therethrough decreasing in diameter downwardly from thelower end of the tubing and forming a restriction 3, which serves as aguide and anchor for the choke assembly. The restriction has a pluralityof duets 4 extending axially therethrough and spaced about the centralbore for the iiow of material through the tting 2 when the -chokeassembly is in the bore thereof.

I viding an upwardly facing shoulder against which the choke apparatusis adapted to seat so as to limit its downward movement. The entrancefrom above into lboth of ythe fittings 2 and 5 is tapered so as to guidethe choke assembly into Still another object of this invention isto'pro-55` place upon being lowered into the well tubing.

On its upper end the tubular'member I Il is provided with a valve seatadapted to receive a ball valve I3 which will permit upward flow butprevent downward flow therethrough. Connected to this upper end andforming a cage or chamber for the ball valve I 3 is a device I4 havinglateral passageways or ports I5 therein so that after oil has passedthrough the bore of the tubular member I and emerged past the valve I3it may flow through the ports I5 and enter the annular space within thewell tubing about the choke assembly and thereafter flow upwardlythrough this annular space.

Secured to the upper end of the cage I4 is the solid body I5 of theholddown apparatus or 'latch assembly which has a slot I1 therethroughin which is disposed the latch dog or pawl I8. This dog is pivotedwithin the slot at its lower .end at I9 and there is a spring 2 arrangedto urge the dog radially outwardly at all times to a position to engagethe shoulder on the lower end of the restriction 3 upon upward movementof the assembly.

Telescopingly engagedover the upper end portion of the body I6 is anactuating sleeve 2l having an opening 22 therein through which the pawlI8 may move into latching position as shown in Fig. 2 of the drawing.The upward and downward movement of the sleeve 2l is limited and thesleeve is prevented from turning on the body I6 by the pin 22 whichextends through a pair of oppositely disposed slots 23 in the sleeve 2Iand is iixedly carried in the upper end portion of the body I6. At itsupper end the sleeve 2I is internally threaded to receive a fitting 24having a pin 25 projecting upwardly therefrom and adapted to receive anordinary iishingtool. The pin 25 may be provided with an opening 2Stherethrough to permit of the attachment of a cable or wire line wherebythe assembly may be lowered into and removed from a well.

It will be realized that when an upward pull is exerted on the pin 25this `will move the sleeve 2l upwardly with respect to the body I5 andwill serve to retract the dog I8 as illustrated in Fig. l. Fitting 24may be omitted and the sleeve 2I may be secured directly to the lowerend of a working barrel of a pump employed to pump fluid from a well.

Whenever it is desired to change the choke I2 either for the purpose ofaltering the internal diameter and hence the permissible iiow from thewell or for the purpose of replacing a worn elementall that is necessaryis to lower the iishing tool over the pin 25 and pull upwardly. Thiswill serve to unlatch the dog i8 as shown in Fig. 1 and thereupon theVentire device may be quickly hoistedr to the surface of the ground.

From the foregoing it will be appreciated that the choke assemblyincluding the latch or holddown assembly can be made of such overall eX-ternal dimensions as to Vpass through the well tubing I regardless ofthe presence of any reasonable restrictions therein and yet be securelylatched in position in the lower portion of the 4 tubing and releasedwhen removal is desired. Also the construction provides for the freeilow of fluid up through the choke tube I0 through cage I4 into thespace within the well tubing Ib about the choke assembly and up throughthe ducts 4 into the well tubing I, when the choke assembly is in itsoperative position.

Having described the invention,we claim:

. 1. A bottom hole choke assembly for well tubing comprising a fittinginterposed in the tubing and having a tapered bore therethrough theminimum diameter of which is at least as Asmall as the minimum interiordiameter of the tubing above said fitting, including restrictions due todevices incorporated therein, said iitting having by-pass ducts to aiorda fluid how path around the portion of said bore of minimum diameter, areleasable/ latch assembly including a body, a latch dog carried by thebody for engagement with the tting, and latch dog retractng means, saidlatch assembly having an overall exterior dimension small enough toenable movement thereof through said tapered bore, a choke carried bythe lower portion of said latch assembly of a diameter small enough topass through the tapered bore, and a seat carried by the tubing belowsaid fitting for receiving the choke.

V2. A bottom hole choke assembly for well tubing. comprising a latchassembly including a releasable latch for latching the assembly in thelower portion of the well tubing, a choke tube, said latch assembly andtube having overall exterior dimensions smaller than the smallestinterior cross section of the well tubing. above .the position at to thelower portion of the latch assembly, said connecting iitting having achamber communicating with the interiory of. said choke tube, said,

chamber having port means placing the interior of the chamber incommunication with the exteat which the choke tube is to be located, afittingvv connecting the upper end of the tube to the lower portion ofthe latch assemblyi said connecting fitting having a chambercommunicating with the interior of said choke tube, said chamber havingport means placing the interior of the chambel` in communication withthe exterior thereof, and means in said Well tubing for centering thelatching assembly therein, said centering means having ducts extendingtherethrough for the flow of material discharged through said port meansinto the space between the latch assembly and the well tubing up intothe well tubing above said centering means.

4. A bottom hole choke assembly for wel1 tubing comprising a latchassembly including a releasable latch for latching the assembly in thelower portion of the well tubing. a choke tube, a ntting connectingv theupperend of the tube to the lower portion of the latch assembly, saidconnecting fitting having a chamber communicating with the interior ofsaid choke tube, said chamber havyingport means placing the interior ofthe chaml which the choke tube is to be located, a iitting connectingthe upper end of the tube.

dimensions smaller than the smallest interiorV cross section of the welltubing above the position at which the choke tube is to be located, afitting connecting the upper end of the tube to the lower portion of thelatch assembly, said connecting fitting having a chamber communicatingwith the interior of said choke tube, said chamber having port meansplacing the interior of the chamber in communication with the exteriorthereof, means in said Well tubing for centering the latching assemblytherein, said centering means having ducts extending therethrough forthe ow of material discharged through said port means into the spacebetween the latch assembly and the well tubing up into the well tubingabove said centering means, and a check valve for preventing flow fromsaid chamber into said choke tube.

6. A bottom hole choke assembly for well tubing comprising a fittinginterposed in the tubing and having a tapered bore therethrough theminimum diameter of which is at least as small as the minimum interiordiameter of the tubing above said fitting, including restrictions due todevices incorporated therein, said fitting having by-pass ducts toafford a iuid flow path around the portion of said bore of minimumdiameter, a releasable latch assembly including a body, a latch dogcarried by the body for engagement with the tting, and latch dogretracting means, said latch assembly having an overall exteriordimension small enough to enable movement thereof through said. taperedbore, a choke, means connecting the choke to the lower portion of thelatch assembly and placing the upper portion of the choke incommunication with the space between the latch assembly and thesurrounding well tubing, and a choke seat in said tubing below saidtting.

'7. A bottom hole choke assembly for well tubing comprising a latchassembly including a releasable latch for latching the assembly in thelower portion of the well tubing, a choke tube, means for suspending thechoke tube from the lower end of the latch assembly with the upper endof the choke tube free to communicate with the space in the well tubingabout the latch assembly, a choke on the lower end of the tube, andmeans for centering said latch assembly in said tubing withoutcompletely closing the space between the latch assembly and the welltubing.

FRANK F. BRIDWELL. CLARA PAULINE MORRISON, Eecutri of the Estate ofGeorge W. Morrison,

Deceased.

REFERENCES CITED The following references are of record in`the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,919,510 Harrington July 25,1933 2,019,978 Hunt Nov. 5, 1935 2,353,652 Coonrod July 18, 1944 Re.20,546 Otis Nov. 2, 1937 2,297,044 Barker et al Sept. 29, 1942

